A vacuum cleaner is an electromechanical appliance utilized to effect the dry removal of dust, dirt and other small debris from carpets, rugs, fabrics or other surfaces in domestic, commercial and industrial environments. In order to achieve the desired dirt and dust removal, most vacuum cleaners incorporate a rotary agitator. The rotary agitator is provided to beat dirt and debris from the nap of the carpet or rug while a pressure drop or vacuum is used to force air entrained with this dirt and debris into the nozzle of the vacuum cleaner. The particulate laden air is then drawn into a dirt collection vessel before being directed through the motor of the suction generator to provide cooling. Finally, the air is filtered to remove any fine particles of carbon from the brushes of that motor or other dirt that might remain in the airstream before being exhausted back into the environment.
Dirt collection vessels on vacuum cleaners typically comprise a dirt cup having a cylindrical sidewall, a tangentially directed air inlet for receiving dirt and debris from the nozzle of the vacuum cleaner, and an axially oriented outlet for discharging clean air from the dirt collection vessel. Such a structural arrangement allows for cyclonic air flow in the dirt cup. Such air flow causes dirt and debris to move outwardly toward the side wall of the dirt cup under the centrifugal force generated by the cyclonic air flow. That dirt and debris is then collected in the dirt cup as the clean air is drawn toward and through the axially directed outlet.
In many vacuum cleaners a filter of some type is provided over the discharge outlet to eliminate any dirt and debris not removed from the air stream by the cyclonic air flow. In other, more recent designs, one or more toroidal cyclones are provided to remove any fine dust particles that may have escaped the first or primary cyclone cleaning stage.
The present invention relates to a vacuum cleaner incorporating a dirt collection vessel of novel design that includes a toroidal toroidal cyclone that provides enhanced cleaning performance.